Violence in the Rakhine State of Myanmar has led to a humanitarian crisis as Rohingya people flee across the border to Bangladesh (1). With the rapid influx of nearly 700,000 arrivals between August 2017 and the beginning of 2018, the Bangladeshi city of Cox's Bazar is now under severe strain from a Rohingya population of almost 1 million, one of the largest concentrations of refugees in the world (2). The crisis seized global attention, and the international response was rapidly escalated to a Level 3 emergency (3). In addition to the humanitarian challenges, the mass influx of Rohingya refugees has resulted in environmental degradation both within the refugee camps and in the surrounding areas (2). The expansion of existing campsites has led to more than 2000 ha of forest loss in the Cox's Bazar region (4). Expansion of the old Kutupalong camp blocked the only corridor used by the globally endangered Asian elephant as a migration route and trapped about 45 elephants in the western side of the camp (5). The latest Rohingya settlement has also amplified humanelephant conflict in the area, with 13 human casualties so far (6). The remaining elephant habitat is under severe pressure from uncontrolled fuelwood collection in the forest (7). The pressure on forests has caused tensions with local

Rigorously computed Penrose diagrams are plotted for a semiclassical model of black hole formation and evaporation, in which black holes form by the accretion of infalling spherical shells of matter and subsequently evaporate by emitting spherical shells of Hawking radiation. The method allows arbitrary interior solutions of the form ds 2 = −f (r) dt 2 +f (r) −1 dr 2 +r 2 dΩ 2 , including singular and nonsingular models. Matter dynamics are visualized by explicitly plotting proper densities and pressures in the diagrams, as well as by tracking the location of trapped surfaces and energy condition violations. The most illustrative model accurately approximates the standard time evolution for black hole thermal evaporation; its time dependence and causal structure are analyzed by inspection of the rigorous diagram. The resulting insights contradict some common intuitions and assumptions, and we point out some examples in the literature with assumptions that do not hold up in our more detailed model. Based on the new diagrams, we argue for an improved understanding of the Hawking radiation process, propose an improved definition of "black hole" in the presence of evaporation, and suggest some implications regarding information preservation and unitarity.